Extra-rapid circuit breaker



June 10, 1930. P. J. BRANCHU 1,763,502

I EXTRA RAPID CIRCUIT BREAKER Filed April 5. 192a Fig.1 Fig.2

Fig 7 Unvenbor v ul Joseph @2122: all u Patented June 10, 1930 UNITED STATES PAUL JOSEPH BRANCHU, OF GUERANDE, FRANCE EXTRA-RAPID CIRCUIT BREAKER Application filed April 5, 1926, Serial No. 99,935, and in France April 8, 1925.

This invention relates to circuit breakers and has special reference to an overload circuit breaker.

One important object of the invention is to provide an improved construction of overload circuit breaker wherein the main circuit is carried through an armature lever form ing a movable contact member and wherein provision is made for preventing the chattering or rapid opening and closing of such lever.

A second important object of the invention is to provide an improved circuit closer of this class wherein the current passing through the armature lever forming the movable contact member is arranged for modifications by the alternations in the main circuit affecting the magnetic field and thereby inducing an auxiliary current flow through such movable contact member.

With the above and other objects in view as will be hereinafter apparent, the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings and specifically claimed.

In the accompanying drawings like characters of reference indicate like parts in the several views, and:

Figure 1 is a diagrammatic view of one form of the circuit breaker adapted for either direct or alternating current.

Figure 2 is a dia rammatic view of a modification likewise a apted for either direct or alternating current.

Figure 3 is a diagrammatic view showing a form of circuit breaker adapted for use with alternating current.

Figure 4 is a diagrammatic view showing a modification of the form shown in Figure 3.

Figure 5 is a diagrammatic view showing a further modification of the form shown in Figure 3.

Figure 6 is a diagrammatic view showing a-second modification of the form which is adapted for use with either direct or alternatmg current,

Figure 7 is a dia rammatic view of a fourth modification o? the first form.

In all of these forms certain of the parts are alike and these parts will now be described. In each form there is an arm or lever a; which forms the armature lever of the circuit closer and at the same time forms a portion of the path for the main current.

The arm a is normally held in closed position by a spring I) which causes the contact point f on said arm to engage'a fixed contact at. The main line conductor h is wound around a magnet M having its ends spaced to provide an air gap and so arranged that when the magnet is energized by excess current flowing through the conductor 72. the magnetic force will be sufficient to move the lever a normally extending through the air gap in such direction as to open contact between the'contacts f and (7. Of course, under these circumstances the spring I) is so proportioned that the normal magnetic effect on the arm a is overcome by the spring and under such normal conditions the main line circuit remains closed, it being understood that the conductor h is connected to the arm a at h which is at or adjacent the pivotal point of said arm. It is also to be understood that this conductor hleads off from the contact d. Thus the magnet winding is a winding of the main circuit conductor about a suitable core and is in series with the arm a and contacts 7 and d. In each of these forms also there is provided a resistance 0. In the 85 form shown in Figure 1 one end of this resistance is connected to the arm a by a conductor 0 and the other end is connected to the conductor h leading from the contact d by a conductor 0 In the form shown inFi re .2 one end of the resistance 0 is connecte by a conductor 0 to a contact finger e which is engaged by the arm a upon the said arm moving to open circuit position.

The remaining end of the resistance a in this and the following forms bein connected by a conductor 0* to the contact In this form the contact e is carried b a fixed su port e. In the form shown in igure 3 a racket g is provided of L-shape and the connection 7L is made to this bracket adjacent the pivot point of the arm a which is carried at the extremity of one arm of the bracket. Also the contact 6 is carried by the extremity of the other arm of said bracket and the resistance a is connected to this last mentioned arm by a conductor 0 It will be noted that in each of these forms, as well as in the form shown in Figure 4, the arm a carries a head 7 wherewith the contact 6 engages.

In the form shown in Figure 4 the arrangement of the parts is similar to that shown in Figure 2 and in fact is identical thereto except that on the arm a there is formed a loop or branch 9 which corresponds in function with the bracket 9 as will be presently understood.

In the form shown in Figure 5 the construction is almost identical with that shown in Figure 4 except that the contact f is moved close to the pivot of the arm a and of course the contact 03 is likewise moved, the arrangement being such that the main circuit passes in the closed position ofthe arm a to the contact f without branching through the loop 9 In the form shown in Figure 6 the contacts f and d are moved toward the pivot of the arm a as in Figure 5 but in place of the contact e arranged for sliding contact over the top of the loop 9 the upper part 1' of the arm a is arranged for sliding contact over an elongated contact 6 which is connected to the resistance a by a conductor 0.

In the form shown in Figure 7 the main conductor h is wound about both arms of the magnet and the support e not only carries the contact 6 but also carries a second contact e which engages the movable end of a second arm j to which the remaining terminal of the resistance 0 is connected by a conductor a, the arms a, and j being connected by a link is having a pin and slot connection with one or the other of said arms and a fixed pivot connection with the remaining arm.

In the form shown in Figure 1 under normal conditions the arm will be in the position shown in full lines so that the current will flow around the core of the magnet M through the winding and thence through the arm a, contact f and contact (1. In case of overload the arm a will be moved to the position shown in dotted lines and contact will be broken between the contacts 7 and 61 so that the main circuit will flow through the winding of the magnet M and through the resistance 0, this resistance thus being in parallel to the normal path through the contacts f and d.

In like manner with respect to Figure 2 the normal flow will be as in Figure 1 but under overload conditions the flow will be through the arm a, contact 6, resistance 0 to the contact d. Thus the resistance is in parallel to the contacts f and d as before although in this case the entire length of the arm conducts the current in either open or closed positions.

In the form shown in Figure 6 in the closed position only the lower part of the arm a will be effective to carry the whole of the main line current, the upper part of said arm carrying only the shunt current when closed and the current through the resistance when open. In the form shown in Figure 7 the full length of the arm a carries the main line current in closed position but when open this current flows only through the lower part of-said arm to the link and thence through the resistance a in the usual manner.

In the forms shown in Figures 3, 4 and 5 the action is much the same as those previously described except that the alternating current passing through the magnet windings sets up oscillations in the magnetic flux so that there is an induced current set up around the loop fonned in Figure 3 by the arm a, contact e and bracket 9 and in Figures 1 and 5 by the loop g and that portion of the arm between the ends of said loop. Thus it can be understood that this induced current will modify the action of the magnet M on the arm a.

Having thus described the invention, what is claimed as new, is:

1. In an overload circuit breaker, a controlling eleetro-magnet having a winding in series in the circuit to be controlled, a conducting lever associated with said magnet and connected in series with said winding in said circuit, a movable contact carried by and conductively connected with said armature lever, a fixed contact engaged by said movable contact upon closing of said circuit, a second fixed contact over which said lever slides and with which the lever is in constant engagement, and a resistance having its terminals connected respectively to said fixed contacts.

2. In an overload circuit breaker, a controlling electro-magnet having a winding in series in the circuit to be controlled, a conducting lever associated with sald magnet and connected in series with said winding in said circuit, a movable contact carried by and conductively connected with said armature lever, a fixed contact engaged by said movable contact upon closing of said circuit, a second fixed contact over which said lever slides and with which the lever is in constant engagement, a resistance having its terminals connected respectively to said fixed contacts, and a member arranged in parallel to said armature lever to form a loop circuit path across the magnetic field of said magnet.

3. In an overload circuit breaker, a controlling electro-magnet having a winding in series in a main circuit to be broken on overload, a conducting lever in seriesin the circuit and traversed by current passing through the circuit and movable in a field excited by the current to an open position, a contact carried by said lever and constituting a movable contact, a stationary contact for engagement by the movable contact, means to yieldably hold the lever in a closed position with its contact engaging the stationary contact, and a resistance in parallel with the contact causing the current to be limited after the lever is opened and pass the lever, whereby the 'electrodynamic forces thus produced tend to keep the lever in its open position until the current falls below a predetermined value.

4. In an overload circuit breaker, a controlling electro-magnet having a winding in series in a main circuit to be broken on overload, a conducting lever in series in the circuit and traversed by current passing through the circuitv and movable in a field excited by the current to an open position, a contact carried by said lever and constituting a movable contact, a stationary contact for engagement by the movable contact, means to yieldably hold the lever in a closed position with its contact engaging the stationary contact, and a resistance in parallel with the contacts causing the current to be limited after the lever is opened and pass the lever, whereby the electrodynamic forces thus produced tend to keep the lever in its open position until the socurrent falls below a predetermined value,

said lever having a side loop extending between arms of the magnet and en a 'ng the lever above and below the same, t e lbop being traversed by a portion of the flux created by the current whereby current induced in the loop tend to increase the acceleration of opening movement of the lever.

Signed at Paris, in the Department of Seine, Republic of France, this twenty-sec- 40 0nd day of March, A. D. 1926.

PAUL JOSEPH BRANCHU. 

